BERLIN, Germany?The historical Berlin wall might be down already for two decades now but the worldwide problem on hypertension and its complications is still up and killing hundreds of thousands of victims annually.

Thousands of hypertension scientists and other experts involved in the treatment of hypertension from all over the world made their way to this historical city to share research data and compare notes which can help clinicians in the better understanding of this prevalent problem.

Hopefully, these new data could translate to the better control of hypertension and its complications. Ongoing is the joint scientific sessions of the International Society of Hypertension and the European Society of Hypertension.

Important clinical challenges

The congress addresses important clinical challenges ordinary physicians get confronted with in their practice and one of these challenges is treating elderly patients with isolated systolic hypertension or ISH. For example, should a 70-year-old patient with a blood pressure (BP) of 170/80 mmHg be treated?

More than 20 years ago, it was believed that the normal systolic BP (the upper number of a BP) is 100 plus one?s age. Now, it has been shown by various studies that neglecting to treat ISH has caused many an elderly to develop stroke and heart attack and cut short their lives.

ISH is defined as an elevated systolic BP with a diastolic pressure (the lower number of a BP) below 90 mmHg. A systolic level of 140 mmHg is already considered elevated particularly in high-risk patients with many risk factors such as diabetes, smoking, obesity, elevated cholesterol, protein leakage in the urine and heart enlargement. ISH is primarily seen in older patients which accounts for 65 to 75 percent of cases of hypertension in this age group.

Data from various long-term studies which have tracked down individuals called cohorts?from the time they were still free of heart disease to the time they developed a cardiovascular problem and suffered from its complications?have shown that the systolic BP gradually rises with increasing age while the diastolic BP falls after age 60 in both normal and untreated hypertensive subjects. The diastolic pressure reaches its peak in the fifth decade and subsequently falls.

Risk factor

Because the systolic and diastolic BPs go in opposite directions after age 60, the pulse pressure which is computed as the systolic BP minus the diastolic BP, increases. The normal pulse pressure is 40 mmHg, as in a BP of 120/80 mmHg. An increased pulse pressure itself has been considered a risk factor for cardiovascular disease. Experts explain that the elevation in pulse pressure is due primarily to diminished arterial compliance making it less flexible and more prone to progression of the atherosclerotic narrowing of the arteries.

Analysis of several studies have been presented confirming earlier ones which showed that ISH is not a harmless entity which can be treated with passive neglect in the elderly. It is associated with a two- to fourfold increase in the risk of heart attack, kidney failure, stroke and shortened lifespan.

Physicians used to be more worried about the diastolic BP in the past, but researchers have now clearly shown that the cardiovascular risk correlates more closely with the systolic than the diastolic BP particularly among the elderly. But even in relatively younger ones?less than 65 years old?there is a progressive increase in the risk of stroke and heart disease with increasing BP, with the risk greater for each increment in systolic BP than for the equivalent increase in diastolic BP.

May do more harm than good

It is therefore now strongly recommended that elderly patients with ISH should be treated. Although experts are certain that antihypertensive therapy can benefit the elderly with ISH, they are also quick to add that bringing down the normal diastolic BP too low as one aims to reduce the elevated systolic BP may do more harm than good. The concern is that the coronary arteries supplying the heart muscles with necessary nutrients fill with blood during diastole, so an excessive fall in diastolic pressure might lead to a paradoxical increase in cardiovascular complications due to diminished coronary artery filling during diastole.

It should change the aggressive orientation for many physicians to learn that for individuals over age 65, although the risk continues to increase with the rising systolic BP, the reverse is true for the diastolic BP. The lower the diastolic pressure at a given systolic BP, the greater the risk, and this is blamed on the increased pulse pressure.

So clinicians may have to temper their goal to bring down the systolic BP to less than 140 mmHg but at the expense of reducing the diastolic BP to less than 70 mmHg. This is called the J-curve in hypertension, so-called because if one looks at the graphs, it assumes a J-shape as the risk paradoxically increases again when the diastolic BP is below 70 mmHg (80 mmHg in some studies).

The J-curve in hypertension can indeed be a kill-joy or an unfortunate kill-life in one?s earnest desire to reduce the BP too low.